• Journal of Biosystems Engineering
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• 제37권5호
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• pp.314-318
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• 2012

Purpose: This study was conducted to develop a measurement system for determining photosynthetic photon flux (PPF) distribution and illumination efficiency of LED lamps. Methods: The system was composed of a linear moving sensor part (LMSP), a rotating part to turn the LMSP, a body assembly to support the rotating part, and a motor controller. The average PPF of the LED lamp with natural cooling and water cooling was evaluated using the measurement system. Results: The PPF of LED lamp with water cooling was 3.1-31.7% greater than that with natural cooling. Based on the measured value, PPF on the horizontal surface was predicted. Illumination efficiency of the LED lamp was slightly increased with water cooling by 3.4%, compared with natural cooling. A simulation program using MATLAB was developed to analyze the effects of the vertical distance from lighting sources to growing bed, lamp spacing, and number of LED lamps, on the PPF distribution on the horizontal surface. The uniformity of the PPF distribution of the LED lamps was fairly improved with 15 cm spacing, as compared to the 5 cm spacing. By simulation, PPF of $217.0{\pm}27.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was obtained at the vertical distance of 40 cm from six LED lamps with 12 cm spacing. This simulated PPF was compared to the measured one of $225.9{\pm}25.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. After continuous lighting of 346 days, the relative PPF of LED lamps with water cooling and natural cooling was decreased by 6.6% and 22.8%, respectively. Conclusions: From these results, it was concluded that the measurement system developed in this study was useful for determining PPF and illumination efficiency of artificial lighting sources including LED lamp.

• 디지털산업정보학회논문지
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• 제7권1호
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• pp.1-9
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• 2011

In this paper, Wireless sensor network technology applied to various greenhouse agro-industry items such as horticulture and local specialty etc., we was constructed automatic control system for optimum growth environment by measuring growth status and environmental change. existing monitoring systems of greenhouse gather information about growth environment depends on the temperature. but in this system, Can be efficient collection and control of information to construct wireless sensor network by growth measurement sensor and environment monitoring sensor inside of the greenhouse. The system is consists of sensor manager for information processing, an environment database that stores information collected from sensors, the GUI of show the greenhouse status, it gather soil and environment information to soil and environment(including weather) sensors, growth measurement sensor. In addition to support that soil information service shows the temperature, moisture, EC, ph of soil to user through the interaction of obtained data and Complex Growth Environment information service for quality and productivity can prevention and response by growth disease or disaster of greenhouse agro-industry items how temperature, humidity, illumination acquiring informationin greenhouse(strawberry, ginseng). To verify the executability of the system, constructing the complex growth environment measurement system using wireless sensor network in greenhouse and we confirmed that it is can provide our optimized growth environment information.

• 조명전기설비학회논문지
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• 제29권2호
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• pp.1-7
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• 2015

The Light Emitting Diode(LED) lighting control system proposed in this thesis is made up of a sensor module, a microcontroller, Bluetooth wireless communication, LED Driver, and LED downlight. The sensor module, comprised of an infrared sensor, an illumination sensor, and a temperature sensor, was designed to one Printed Circuit board(PCB). The system is able to identify the environment information collected by the sensor, and make it possible to control lighting automatically and manually through sensors. In addition, depending on users' conditions, a color temperature can be controlled. CS-1000, a spectroradiometer, was employed to measure the changing values of a color temperature in 8 steps. According to a test, it was found that it was possible to change a color temperature from 3187K of Warm White LED to 5598K of Cool White LED. The Bluetooth based wireless communication technique makes it possible to control more lighting devices than other wireless communication techniques does.

• Current Optics and Photonics
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• 제5권3호
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• pp.298-305
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• 2021

Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

• 전기전자학회논문지
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• 제26권3호
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• pp.422-429
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• 2022

조도센서 칩은 아날로그 회로의 트리밍이나 디지털 레지스터의 초기 값을 셋팅하기 위해 소용량의 eFuse(electrical Fuse) OTP(One-Time Programmable) 메모리 IP(Intellectual Property)를 필요로 한다. 본 논문에서는 1.8V LV(Low-Voltage) 로직 소자를 사용하지 않고 3.3V MV(Medium Voltage) 소자만 사용하여 128비트 eFuse OTP IP를 설계하였다. 3.3V 단일 MOS 소자로 설계한 eFuse OTP IP는 1.8V LV 소자의 gate oxide 마스크, NMOS와 PMOS의 LDD implant 마스크에 해당되는 총 3개의 마스크에 해당되는 공정비용을 줄일 수 있다. 그리고 1.8V voltage regulator 회로가 필요하지 않으므로 조도센서 칩 사이즈를 줄일 수 있다. 또한 조도센서 칩의 패키지 핀 수를 줄이기 위해 프로그램 전압인 VPGM 전압을 웨이퍼 테스트 동안 VPGM 패드를 통해 인가하고 패키징 이후는 PMOS 파워 스위칭 회로를 통해 VDD 전압을 인가하므로 패키지 핀 수를 줄일 수 있다.

• 한국기계가공학회지
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• 제9권5호
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• pp.57-63
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• 2010

Tolerance analysis is one of the most important processes to improve the image quality of products. High resolution camera module for mobile phones needs precision assembly technology since the module becomes smaller and thinner. This paper will focus on the unit tolerance and the assembly tolerance which can affect the performance of the module. Lens shading and relative illumination were used to evaluate the optical axis scatter for each component on camera and estimate the assembly yield rate based on the evaluation result. A program was developed to analyze the impact on optical axis by each module, then to optimize the dimensions and tolerance for reducing the scatter of optical axis assembly. Through the simulation, though a rate of relative illumination was declined in where optical axis is displaced $100{\mu}m$ from sensor center, MTF performance is not influenced by increasing in optical axis displacement. It was seen that assembly yield was improved in result of simulation after correcting optical axis tolerance.

• 동굴
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• 제86호
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• pp.25-30
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• 2008

동굴내 환경보존을 위해서는 동굴내 관광객 통로 안내용 전기 조명을 계속 켜고 있는 것을 유도 등이나 윙카로 교체하고, 동굴내 관광객을 위하여 설치한 전기조명을 콘센트에 센서등을 추가로 설치하여 사용한다면, 현재보다 더 많은 전기 절감을 할 수 있으며 특히 성수기보다 비수기에는 더욱 더 많은 전기 절감을 할 수 있을 것으로 예상된다.

• 전자공학회논문지SC
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• 제44권3호
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• pp.29-33
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• 2007

균일한 빛 에너지에 대하여 영상센서의 모든 픽셀은 이상적으로는 균일하게 반응해야하지만 실제적으로는 그렇지 않다. 이러한 영상센서의 불균일 특성은 픽셀자체의 특성과 광학모듈 특성 등에 의하여 발생한다. 영상센서의 불균일 특성은 고정된 형태의 잡음으로 다양한 보정 알고리즘에 의해 보정될 수 있으며 보정능력에 따라 더욱 우수한 영상 품질을 기대할 수 있다. 보통, 영상센서의 불균일 보정은 적절한 알고리즘에 의해 보정계수를 구한 후 이를 적용하여 이루어진다. 본 논문에서는 모든 광량영역에서 좀 더 정확하고 신뢰성 있는 최적의 픽셀 불균일 보정계수 계산 알고리즘을 제안한다. 제안한 알고리즘은 불균일 특성을 향상시키기 위해 센서를 1차원으로 모델링하였으며 보정계수를 구하기 위해 여러 광량레벨에서 측정데이터를 얻고 최적의 해를 얻기 위해 최소자승법을 이용한다. 논문에서는 보정계수 획득을 위해 적분구, 프래임그래버를 탑재한 컴퓨터 및 제안한 알고리즘을 구현한 소프트웨어를 사용하였다. 또한 자체 구현한 카메라와 별도의 시험셋업을 이용하여 불균일 시험을 수행하여 제안한 알고리즘을 검증하였다. 제안한 알고리즘을 보정 전 결과 및 기존 방법의 결과와 비교하였으며, 비교 결과, 제안한 알고리즘이 모든 광량에서 가장 좋고 신뢰성 있는 결과를 보여주었다.

• 전기학회논문지
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• 제60권7호
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• pp.1391-1395
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• 2011

In this paper, would implement a transceiver for the visible light communication that based on wireless communication driving technology for LED illumination-based infrared ray communication, and measurement analyzed a design error rate of a transceiver variable rate has made about distance change -2.5m. The error rate measured a voltage variable along illuminate change between switchable circumstances, which has illuminated insight and outright. Each analyzed and measurement on the communication distance errors along the differences of disturbance light between night and days. The LED module has implemented for number of 6 through illumination dimming in case of different values. Also, implementation for the system module of a VLC transceiver based on the infrared sensors which used feedback outcome value has analyzed with error rate.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2019년도 제59차 동계학술대회논문집 27권1호
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• pp.357-358
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• 2019

본 논문에서는 조도센서와 마이크로웨이브센서 기반의 협력제어를 통하여 기존대비 35%P 전력절감이 가능한 에너지 절감형 스마트 LED 조명시스템에 대하여 기술하였다. 제안된 시스템은 센서모듈과 LED조명, 무선전송 모듈이 분리된 형태로 인지기반 조명 제어를 통하여 ESCO 사업에 적합한 에너지 절감형 융합 조명 시스템에 다양하게 활용될 수 있다.